docs: def get_consumer_cfg(config, only, qty):
          """Get the consumers config, possibly filtering the config if only
          or qty is set.
  
          :param config: The consumers config section
          :type config: helper.config.Config
          :param str only: When set, filter to run only this consumer
          :param int qty: When set, set the consumer qty to this value
          :rtype: dict
  
          """
          consumers = dict(config.application.Consumers or {})
          if only:
              for key in list(consumers.keys()):
                  if key != only:
                      del consumers[key]
              if qty:
                  consumers[only]['qty'] = qty
          return consumers